Top ten record climbing following article (4)
I believe the answer is:
apex
'top' is the definition.
(apex is a top or peak)
'ten record climbing following article' is the wordplay.
'ten' becomes 'X' (Roman numeral).
'record' becomes 'EP' (abbreviation for extended play record).
'climbing' says the letters should be written in reverse (in a down clue, letters climb up).
'following' says to put letters next to each other.
'article' becomes 'a' (the indefinite article in English).
'x'+'ep'='xep'
'xep' in reverse letter order is 'pex'.
'pex' after 'a' is 'APEX'.
(Other definitions for apex that I've seen before include "Top, highest part" , "The highest point of something" , "Uppermost tip" , "climax" , "Tip -- top" .)